The three-storey building and surrounding infrastructure has to be built and operational before the first train pulls into town in December, 2014.
But the brakes have already been put on the project after transport company First lodged an objection to a Compulsory Purchase Order being pursued by the local authority for the current bus station.
And it is likely to take a lengthy public enquiry to settle the land dispute.
This week's full planning application highlights in detail the new building which will welcome both train and bus passengers to the town - and even the wider Borders.
As well as housing office accommodation and toilets, the interchange will also have retail outlets, a cafe and a large reception area.
A new civic space will be created as well as a new car park and riverside walkways and cycle paths.
A spokesman for Scottish Borders Council said: "One of the key design parameters is to maximise the benefits to Galashiels from the reintroduction of the Borders Railway, through the provision of a gateway statement building and strong link between the railway and the town centre.
"It has been demonstrated that the design of both the new transport interchange and associated public realm integrate, enhance and promote the key pedestrian route between the railway and the town centre.
"The design of the building is contemporary whilst also responsive to the surrounding architectural heritage. The unique and distinctive form ensures an identifiable building that is memorable to those visiting Galashiels and the Scottish Borders."
A public exhibition of the outline plans was held almost 18 months ago with around 250 people turning up for a look.
And local councillor Bill White believes the landmark building and newly developed riverside area will be a hit with both locals and tourists.
Mr White said: "This will be the largest municipal building project that Scottish Borders Council has been involved with - it will make a statement for everyone arriving in the town. The whole area from the transport interchange down to Douglas Bridge will be much nicer once all of this work is done."
Although the full application still has to overcome the planning process, as well as CPOs being completed for the surrounding land, Councillor White is confident the building will be completed before the train comes in. He added: "Being a modern building it can go up a lot quicker than traditional buildings. There's not a lot of time before the trains come but we will be ready."
Fellow councillor Sandy Aitchison admits it took him time to warm to the modern design. Councillor Aitchison said: "I wasn't too sure of the building to start with but it has grown on me. I have to say I really like it now.
"There's been a lot of consultation and a lot of people have had their say."